1. Field of the Invention.
This invention relates to supporting stakes or poles and particularly to such stakes or poles adapted for agricultural applications.
2. Prior Art.
Prior art stakes came in many configurations, such as with a channel cross-section and with vertically spaced hooks, notches or dimples to hold the wires in place. The channel cross-section did not represent an optimum strength for the weight or thickness of the steel used to make the stake. Further, if an attempt were made to minimize the gauge of the steel used the stakes or posts could not withstand the forces, particularly torsional forces, to which the stakes were subjected from time-to-time when, for example, agricultural machines, such as mechanized pickers, hit the wires supported by the stakes. Further, wire heights were dictated by the relatively widely-spaced hooks, notches or dimples on the stakes. Such hooks, notches and dimples removed metal and destroyed the integrity of the fabricated form thereby diminishing the torsional and flexural strength of the stakes. Furthermore, hooks and notches either break-off allowing the wire or wires to drop to the ground, with their fruit load, or eventually cut the trellis wire or wires with the same result.
Many of those problems were solved by my grape stake described in my U.S. Pat. No. 4,258,523 issued Mar. 31, 1981. However, in the field use of the patented stake certain problems arose which led me to make this invention. One of the uses for my stake is in vineyards. Because of the high cost of labor today, mechanical harvesters are now employed in the vineyards. Those mechanical harvesters operate on the principle of shaking the vine rather violently, causing the bunches of grapes to be separated from the vines and, thence, collected. Beater rods and shaker bars are utilized in the harvester and as the harvester moves down a row of grapes in the vineyard it strikes the poles supporting the vines. Two undesirable results occur.
First, the beater rods and shaker bars become damaged when they suddenly encounter the flat flanges on my patented post. This results in frequentand expensive replacement of those rods and bars.
On the other hand, the posts, when encountered by the beater rods and shaker arms of the mechanical harvester, suffer unusual stresses of both a torsional and flexural nature. Also, with conventional posts using notched edges or hooks, the supported wire is severly abraded and may be seriously weakened during the harvesting process.
It is an object of my invention, therefore, to overcome the general problems and disadvantages set forth hereinbefore.
It is a further object of my invention to provide an improved stake with great flexibility in wire positioning, great torsional and flexural strength and compatibility with mechanical harvesting apparatus.